title: Timing of mating and ovarian response in llamas (Lama glama) treated with pFSH.
abstract: The effect of the timing of mating on ovarian response in llamas was evaluated using 20 adult llamas weighing 90-120 kg which had been in oestrus for 5 days and were treated with 20 mg pFSH every 12 h for the following 5 days (total dose: 200 mg of FSH-NIH-P1). They were randomly allocated to Group A (N = 10) and mated immediately at the end of pFSH treatment or to Group B (n = 10) and mated 36 h after the end of pFSH treatment. Llamas of both groups were given hCG (750 iu, i.m.) immediately after mating. A second mating was allowed 12 h later. Ova and embryos were recovered by non-surgical uterine flushing 7 days after the first mating. Ovarian response was immediately evaluated afterwards via laparoscopy. The mean ovulation rate of 4.5 corpora lutea for Group A was significantly lower (P < 0.01) than the mean of 13.8 observed for Group B. The total ovarian response (number of corpora lutea + follicles > 10 mm) was also significantly higher (P < 0.01) in Group B than in Group A. Twenty-seven ova were recovered in each group, corresponding to 60% and 20% (P < 0.01) of the corpora lutea observed in Groups A and B, respectively; however, no significant difference (P > 0.05) in fertilisation rate was observed. The results show that pFSH induces superovulation in llamas treated during oestrus and that a 36-h interval between the end of FSH treatment and mating increases ovulation rate and the total ovarian response but does not affect the number of ova/embryos recovered.
authors.affiliation: Animal Reproduction Institute, Faculty of Veterinary Sciences, Universidad Austral de Chile, Valdivia, Chile.
authors.forename: M H
authors.initials: MH
authors.lastname: Ratto
authors.forename: R
authors.initials: R
authors.lastname: Gatica
authors.forename: J E
authors.initials: JE
authors.lastname: Correa
mesh_terms: D000818:Animals; D002161:Camelids, New World / Q000502:physiology*; D015331:Cohort Studies; D004971:Estrus / Q000187:drug effects / Q000502:physiology*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D010062:Ovulation Induction / Q000379:methods*; D011897:Random Allocation; D012726:Sexual Behavior, Animal; D013480:Superovulation / Q000187:drug effects / Q000502:physiology*
chemical_list: D005640:Follicle Stimulating Hormone